error C2660: 'MouseListener::MousePressed' : function does not take 4 arguments

Question

Im working on an c++ pseudo graphic button for a school assignment. I use the observer pattern.

in Button.cpp:

void Button::notify()
{
    for (int iterator = 0; iterator < listeners.size(); iterator++)
    {
        listeners[iterator]->MousePressed(*this, x, y, isLeft);
    }
}

as you can see the MousePressed function receive 4 arguments but i get:

function does not take 4 arguments

in Button.h:

struct MouseListener
{
    virtual void MousePressed(Button &b, int x, int y, bool isLeft) = 0;
};

class Button : public Label
{
public:

    vector <MouseListener*> listeners;
.
.
.

in main:

struct MyListener : public MouseListener
{
    MyListener(iControl &c) : _c(c) { }
    void  MousePressed(Button &b, int x, int y, bool isLeft)
    {
        _c.setForeground(Color::Red);
    }
private:
    iControl &_c;
};

int main(VOID)
{

errors:

Error 2 error C2061: syntax error : identifier 'Button' c:\users\gonen\unitedproj\unitedproj\Button.h 14 1 unitedProj

Error 4 error C2061: syntax error : identifier 'Button' c:\users\gonen\unitedproj\unitedproj\Button.h 14 1 unitedProj

Error 5 error C2660: 'MouseListener::MousePressed' : function does not take 4 arguments C:\Users\Gonen\unitedProj\unitedProj\Button.cpp 24 1 unitedProj

when the first two are for the declartion in main and the last is in the use of the function in Button.cpp. help? when im standing with the mouse curser on the function in Button.cpp i get:

void MouseListener::MousePressed(Button &b,int x,int y, bool isLeft)

I just need this to work so i can move on and let the rest of the group members to use the button in the controls they implementing... and move on to the next i need to do :-(

edit: thank you for the fast answer. I tried to do what you asked. now i get:

*Error 3 error LNK2019: unresolved external symbol main referenced in function __tmainCRTStartup C:\Users\Gonen\unitedProj\unitedProj\MSVCRTD.lib(crtexe.obj) un‌itedProj

One basic syntax error can generate a flurry of other errors. Always start at the top of the error list, **never** the bottom. — Hans Passant, Jun 15 '16 at 16:14
Note: `VOID` is defined to `void`, so `int main(VOID)` looks weird but will work. [Windows Data Types (Windows)](https://msdn.microsoft.com/en-us/library/windows/desktop/aa383751(v=vs.85).aspx) — MikeCAT, Jun 15 '16 at 16:18

score 0 · Accepted Answer · answered Jun 15 '16 at 16:08

Button is not declared at the point where MousePressed is declared, so it cannot be used. I suggest you should use forward declaration.

class Button; // add this line

struct MouseListener
{
    virtual void MousePressed(Button &b, int x, int y, bool isLeft) = 0;
};

class Button : public Label
{
public:

    vector <MouseListener*> listeners;
.
.
.

error C2660: 'MouseListener::MousePressed' : function does not take 4 arguments

1 Answers1